Arria 10 EPCQL Controller

Here is a copy pasta of the code from the NIOS driver:

 /* calculate current sector/block number */
    sector_number = (block_offset/(epcq_flash_info->sector_size));
    /* sector value should occupy bits 23:8 */
    mem_op_value = (sector_number << 8) & ALTERA_EPCQ_CONTROLLER2_MEM_OP_SECTOR_VALUE_MASK;
    
     /* write enable command */
    mem_op_value |= ALTERA_EPCQ_CONTROLLER2_MEM_OP_WRITE_ENABLE_CMD;
    /* write sector erase command to EPCQ_MEM_OP register to erase sector "sector_number" */
    IOWR_ALTERA_EPCQ_CONTROLLER2_MEM_OP(epcq_flash_info->csr_base, mem_op_value);
    /* sector value should occupy bits 23:8 */
    mem_op_value = (sector_number << 8) & ALTERA_EPCQ_CONTROLLER2_MEM_OP_SECTOR_VALUE_MASK;
    /* sector erase commands 0b10 occupies lower 2 bits */
    mem_op_value |= ALTERA_EPCQ_CONTROLLER2_MEM_OP_SECTOR_ERASE_CMD;
    /* write sector erase command to EPCQ_MEM_OP register to erase sector "sector_number" */
    IOWR_ALTERA_EPCQ_CONTROLLER2_MEM_OP(epcq_flash_info->csr_base, mem_op_value);
    
    /* check whether erase triggered a illegal erase interrupt  */
    if((IORD_ALTERA_EPCQ_CONTROLLER2_ISR(epcq_flash_info->csr_base) &
                    ALTERA_EPCQ_CONTROLLER2_ISR_ILLEGAL_ERASE_MASK) ==
                            ALTERA_EPCQ_CONTROLLER2_ISR_ILLEGAL_ERASE_ACTIVE)
    {
        /* clear register */
        /* EPCQ_ISR access is write one to clear (W1C) */
        IOWR_ALTERA_EPCQ_CONTROLLER2_ISR(epcq_flash_info->csr_base,
            ALTERA_EPCQ_CONTROLLER2_ISR_ILLEGAL_ERASE_MASK );
        return -EIO; /* erase failed, sector might be protected */
    }